Electrical deep well reciprocating pump assembly



June 5, 1945. A. ARUTUNOFF T 2,377,743

ELECTRICAL DEEP WELL RECI PRQGATING PUMP ASSEMBLY Filed March 1, 1941 I4 Sheets-Sheet HTTORNEX June 5, 1945. A. ARUTUNOFF ELECTRICAL DEEP WELLRECIPROCATING PUMP ASSEMBLY 4 Sheets-Sheet 2 Filed March 1, 1941 a w% mNf T J1me 1945- -A. ARUTUNOFF 2,377,743

ELECTRICAL DEEP WELL RECIPROCATING PUMP ASSEMBLY Filed March 1, 1941 '4Shets-Sheet s INVENTOR.

, Patented June 5, 1945 ELECTRICAL DEEP WELL BECIPBOCATING PUMP ASSEMBLYArmais Arutunofl, Bartlesvllle, Okla asslgnor to Reda Pump Company,Bartlesvllle, th., a corporatlon of Delaware Application March 1, 1941,Serial No. 381,296

9 Claims. (Cl. 172-239) My invention relates to electrical deep wellreciprocating pump assemblies and more particularly to a pump and motorassembly adapted to be lowered to the bottom of a well whereby areciprocating pump will be driven directly from an electric motor,together with electrical mean for reversing the same to obtain thereciprocating motion.

This application is an improvement over my copending application, SerialNo. 328,419, filed April 8,1940.

In many areas, after the gas pressure in a field has been depleted, itis necessary to pump the oil out of the well. At present, there are twotypes of pumping equipment available. One is known as the Reds. pumpwhich comprises a multistage centrifugal pump and motor assembly. Theassembly is adapted to be lowered into the well and to pump the oil outof the well without the necessity of using a long string of sucker rods.The other type of pumping equipment available comprises a reciprocatingpump which is actuated through a string of sucker rods operated by anysuitable means such as a motor driven walking beam. The pumping of oilwith sucker rods has many disadvantages. The cost of the string of rodsand the time consumed in placing the rods and removing them when it isnecessary to replace valves and the like, is considerable. Sucker rodsfrequently break, resulting in the shutting down of pumping operationsand the necessity of fishing for the broken rod string. The powerconsumed in reciprocating a long string of rods is so much waste in sofar as the removal of oil from the well is concerned.

One object of my invention is to provide a novel motor and reciprocatingpump assembly adapted to be lowered into the Well, whereby oil may bepumped from the well. by the reciprocating pump without the necessity ofmoving a long string of sucker rods.

Another object of my invention is to provide a pumping assembly whichmay be installed and removed from the well as a unit avoiding the time,labor and expense of handling a plurality of sections of sucker rods.

Another object of my invention is to eliminate wiring by the use of thepower supply lines and lines for actuating the reversing mechanism in asingle circuit, and utilizing the eduction tubing as a conductor in saidcircuit.

Another object of my invention is to provide a motor and reciprocatingpump assembly having novel means for reciprocating the pumping means.

Other and further objects of my invention will appear from the followingdescription.

In the accompanying drawings which form part of the instantspecification and are to be read in conjunction therewith and in whichlike reference numerals are used to indicate like parts in the variousviews;

Figure l is an elevation of a motor pump assembly showing one embodimentof my invention.

Figure 2 is an enlarged sectional view of a portion of my pump assemblydirectly beneath the motor housing.

Figure 3 is an enlarged sectional view of a portion of the pump assemblydirectly below the portion shown in Figure 2.

Figure 4 is an enlarged sectional view of a portion of the pump assemblydirectly below that portion shown in Figure 3.

Figure 5 is a sectional view on an enlarged scale of the bottom sectionof my pump assembly.

Figure 6 is a sectional view of a portion of the pump assembly taken inthe vicinity of the portion shown in Figure 2 but at right anglesthereto and showing the parts at the limit of the upstroke.

Figure 7 is a sectional view taken on the line 'i-l of Figure 2.

Figure 8 is a sectional view taken on the line 3-8 of Figure 2.

Figure ii is a sectional view taken on the line il of Figure 3.

Figure id is a sectional view taken. on the line ill-89 of Figure 3.

Figure 11 is a diagrammatic view showing the electrical circuitsinvolved.

Referring now to the drawings, the assembly is capped with a forging icommunicating with eduction tubing it through which the liquid isdelivered to the surface. The forging l is provided with serrations 3,adjacent the upper end thereof, adapted to receive suitable loweringclamp and fishing tools. The forging l is connected by a tube 5 to ahousing ii in which the electrical motor is positioned. The motorhousing 5 is connected to the tube 4 by means of a fitting 6. Power isfurnished to the motor through a cable '27. A connector 8 joins themotor assembly to the pump assembly. The connector 8 is bolted to ahousing by means of bolts l0, as can readily be seen by reference toFigure 2. The housing 9 contains the thrust bearings II. The motor shaftterminates in the splined end I! which is connected by connector 13 to ashaft I4 which is provided at its lower end with an elongated threadedportion IS. A connecting section I 8 is threaded to a housing I! towhich a packing housing I3 is secured. The packing housing I3 supports aconnecting fitting I3 to which the pump barrel 23 is secured. A footvalve housing 2| i supported by the pump barrel 23. A nut 22 engages athreaded portion I5 of the acialating shaft through the medium of aplurality of ball bearings 23. The ball bearing nut 221s a tool of theart and it is understood that any suitable form of nut and thread'meansmay be employed. The screw is of small gauge and in this case I usedsmall balls to allow a high rotation with a slow reciprocating speed ofthe nut 22. The nut 22 carries an upper skirt 24. The skirt 24 is reallyan annular piston adapted to enter an annular cylinder 25, formed bytubular member 25 and the walls of the connecting section I 4. Theannular cylinder 25, as well as the entire housing is normally filledwith oil and acts as a hydraulic brake, as will hereinafter be describedmore fully. The upper portion of the cylinder is normally closed by aring 23' provided with a plurality of ports 21, normally closed by checkvalves 23. The clearance at the entrance 23 of the annular cylinder 25and the annular piston 24 is normally about two thousandths of aninch'(.002") A tube 33 alongside the pump assembly contains conductors3i leading to the control circuit. One oi. these conductors makescontact through an opening-normally closed by a plug 32 with a contactwhisker 33.

A connecting tube 34 is threadedly secured to the lower portion of thenut 22 and carries at its lower end another annular piston 35. The pumprod 36 is also secured to the member 35 as can readily be seen byreference to Figures 3 and 9. The annular piston 35 is adapted to enterthe annular cylinder 31, shown in Figures 3 and 4. The annular piston 35and-the annular cylinder 31 act as a hydraulic brake for the limit ofthe downstroke, as will be more fully described. The conductor housingtube 33 contains a control conductor 38, which makes electricalconnection with a contact whisker 33 as can readily be seen by referenceto Figure 3, through an opening normally closed by a plug '43, I

The lower end of the actuating screw I5 is prevented from moving in ahorizontal plane by means of a guide member 4|, housed in a floatingcentering plate 42. The plate 42 is provided with a plurality ofopenings 43 to permit the free passage of oil.

the lower end thereof. The member 35 is provided with a plurality ofholes 44 to permit the free passage of oil during the reciprocation ofthe pump rod and nut. Splines 45 and 43 are secured to the interior ofhousing II, as can readily be seen by reference to Figures 6, '1, 8, 9,and 10, to prevent the nut from turning with the screw. The splinesallow reciprocation of the nut and associated parts, while preventingtheir rotation relative to the housing. The annular cylinder 31 isclosed by a ring 41, fitted with a plurality of relief ports 48,normally closed by check valves 43. The annular cylinder 31 is supportedfrom the walls of the housing II by means of a ring 53. The space withinthe housing I! below the ring 53 forms an annular area 5i in which ispositioned a floating piston 52 provided with packing members 53 and aplurality of ports 54 and 55. Ports 54 discharge into the space belowthe piston while ports 55 discharge into the space above the piston.Check valves 53 seat upwardly, while check valves 53 seat downwardly.The lower side of the floating piston communicates with the fluid It isto be noted that the pump rod 33 is secured to the member 35 centrallyof in the well through a port 53. The piston moves to compensate forpressure differentials produced in housing I1 by reciprocation of thepumping and reversing mechanism. A tube 13 forms the inner boundary ofthe annular space in which the piston moves and houses the pump rod 35.The pump rod 35 passes through a packing section II containing packing II. A port I2 permits leakage from the pump to be discharged into thewell.

The pump rod 35 carries at its lower end the pump piston or plunger I3operating within the pump barrel 23. The pump is a double acting one. Onthe upstroke, fluid from the well passes the check valve I4 and flowsinto the pump barrel beneath the plunger I3. At the same time, fluidabove the plunger i lifted, flowing through fltting 15 past check valveI6, through eduction tubing I3. On the downstroke, fluid below theplunger I3 previously taken into the pump barrel, flows outwardlythrough fitting I3, past check valve 33, through eduction tubing 3|, Onthe downstroke, fluid from the well passes through intake port 32, pastcheck valve 33 into the pump barrel above the plunger.

In operation, the motor within housing 4 is rotating the actuating screwI5 through the splined shafts I2 and I4 and the connector I3. Let usassume that the screw shaft I5 is turning in a direction to move the nut22 upwardly. The upward motion of the nut 22 carries the connecting tube34, the member 35 and the pump rod 35 upwardly, thus carrying theplunger 13 upwardly and lifting oil above the plunger upwardly and outthrough the connection I5 and eduction tubing 13, thence into the hollowforging I and out of the eduction tubing 2 to the surface. In theposition shown in Figure 2, it will be noted that the whisker 33 whichpasses through plug 32 in an insulating bushing 34 (as can be seen byreference to Figure 7) has made contact with the annular piston 24.

Referring now to Figure 11 where I have shown a diagrammatic view of theelectrical circuits involved, the three conductors 33, 3|, and 32 arethe three supply lines of the three-phase alternating current. The fieldwinding for the induction motor which may have a squirrel cage rotor, isshown diagrammatically by the three branches 33, 34, and 35. The windingproduces a rotating field which is followed by the squirrel cage rotorof the motor. In the position of parts shown in Figure 11, line 33 isconnected to windmg 34 throughconductor 36 and contact point 31,\contact point 33, contact point III, contact point I I2, conductor 33and conductor I33. Similarly, main line wire'ili is connected to winding33 of the field through conductor I3I, contact point I32, contact pointI33, contact point I44, contact point I35, conductor I 36, conductorI31, the winding I33 oi the overload relay, and conductor I33. The mainline wire 32 is directly connected to winding 35 through conductor Ill.With the three branches of the Y-connected field winding, a rotatingfield, rotating in one direction, will be produced. Contact points 33,III, I33 and I34 are held in contact with contact points 31, H2, I32 andI35 respectively by the armature I I 3, due to the energization of thewinding II4 by current flowing from main line wire 33 through conductorH5, conductor H5, conductor I I1, through winding II4, through conductorII3, through conductor II3, through contact point I23, throughconducting member I, through conductor I22, thence to main lineconductor 32, thus completing a circuit between main line wires 33 and32.

Contacting of contact point I with conducting member I2I also completesthe circuit from main line wire 33 through conductor II3, throughconductor II3, through conductor I 23, through conductor I23, throughwinding I21 of the time delay relay, thence through conductor I23 toconductor II3 to contact point I20 to conducting member I2I to conductorI22, to main line wire 32. The energization of winding I2'I ejectsarmature I23, completing the circuit between contact points I30 and I32,thus conditioning the circuit for the reversing action which will behereinafter described.

It will be observed that the reversing switch comprises a pivoted armI33 connected at its ends to armatures H3 and I34. Armature I34 ispushed upwardly when the winding I33 is ener-' gized.

when the whisker 33 contacts with the annular piston 24, current willflow from main line wire 32 through conductor IIII, through conductorI33, through conductor 3| and thence to piston 24 through whisker 33.This circuit from main line wire 32 through whisker 33 to piston 24 iscompleted through the metal parts of the pumping mechanism and eductlontubing 2 diagrammatically shown in Figure 11 as a conductor I33. .(Thiscircuit may or may not be grounded as shown at I33.) From the eductlontubing 2 the circuit is completed through conductor I43, through contactpoint I32, through conducting member I, through contact point I30,through,

conductor I42, through the winding I24, through conductor I43, throughconductor II5, to the main line wire 33. The energization of winding I24will attract the armature I23, pivoting the arm I44 so that theconducting member I2I will make contact with contact point I43. Whenthis occurs, the coil II4 will be deenergized, while the coil I33 willbe energized by current flowing from main line wire 33 through conductorI I3, through conductor IIG, through conductor I", through winding I33,through conductor I43, through conductor I41, through contact point I43,through conducting member I2I, through conducting member I22 to theother main line wire 32. The energization of winding I33 will movearmature I34 upwardly. When this occurs, main line wire 33, theretoforeconnected to winding 34, will be annular piston 24 upwardly aconsiderable distance before the direction of rotation is changed. Thewhisker 33, therefore, will remain grounded for a considerable period ortime.

It will be noted, further, that when the circuit is broken betweencontact point I20 and the conducting member I2I, that the coil I21 willbe deenergized, thus permitting armature I23 to break the circuitbetween contact points I33 and I32, thus deenergizing coil I24. Theswitching action, however, has already taken place by this time and thelatching relay is such that the conduct ing member I2| will be held incontact with contact point I43. Besides energizing th winding I33, thelatching relay also completes the circuit from line wire 30 throughconductor II3, through conductor II3, through conductor I23, throughconductor I33, through winding I30, through conductor I3I, throughconductor I41, through contact point I43, through conducting member I2I,through conductor I22, back to the other side of the line 32. Theenergizaticn of winding I30 will raise armature I32. The raising ofarmature I32, however, is delayed by any suitable means to introduce atime delay as is well known in the time delay relay art. This delays thecompletion of the circuit between-contact points I33 and I34 by theconducting strip I33 a sufllcient length of time to enable the screw I3to move the nut 22 downwardly a suflicient distance so that the whisker33' is out of contact with the annular skirt of piston 24; After thecircuit has been broken by the downward movement of the nut, a circuitis completed through contact points I33 and I34 so that, when whisker 33contacts the annular piston 33 at the bottom of the stroke, current willflow fom main line wire 32 through conductor IIII, through conductorI33, through conductor I33, through whisker 33, piston 35,

through metal parts-of pumping mechanism conconnected to winding 33through conductor I43, I

contact point I43, connecting strip I50, contact point I 3i, conductorI3'I, winding I03, and conductor I03. Similarly, main line wire 3I whichhad been connected to winding 33, will be disconnected from winding 33and connected to winding 34 through conductor I52, contact point I33,conducting strip I34, contact point I53, conductor I33, and conductorI33. The reversal of the main line connections to coils 33 and 34 willreverse the direction of rotation of the rotating held of the inductionmotor, thus producing a reversal in the direction of the driving screwI3. The latching relay is of the type which takes positive energizationof one of its actuating coils to operate it. In other words, It willremain in the position shown in the drawings until coil I23 is energizedin the manner just described. It was moved to the position shown in thedrawings by a previous energization of coil I31 acting through armatureI53 and the pivoted arm I44.

It takes an appreciable interval of time for the rotating held to haveeffect, and ordinarily the inertia of the rotor is such that it willmove the thence through conductor I43 and conductor II5 to the otherside of the line 30. It will be seen that the whisker contactsalternately, grounding at the top and bottom of each stroke effects areversal of the direction of rotation of the actuating screw 83.

If for any reason, due to the insulating action of the oil ordisarrangement of the whisker contacts, a reversal should not .takeplace, I have provided another means'of reversing. It will be observedthat the annular skirt 23 is a piston having small clearance with theannular cylinder 23. In the position of the parts shown in Figure 6, theannular piston 24 is shown a considerable distance within the annularcylinder 23. Oil in the cylinder 23 is displaced by the pistondownwardly through the small clearance at the mouth of the annularcylinder. It will be seen that we have a species of hydraulic brake. Theincreased load introduced to the motor by the braking action, that is,by the work expended in'forcing oil past the small clearance between theannular piston and the cylinder mouth, produces a temporary overload sothat there is a surge of current through the winding I03 of the overloadrelay. .When this occurs, the armature III is raised, carrying with itconducting strip II2, completing the circuit across contact points "3and II4.- When this occurs, a circuit. is completed through one or theother of winding I21 or I3I, depending on whether armature I23 is raisedor armature I82 is raised. In the position of parts shown in Figure 11,when the circuit is completed across contact points I13 and I'll,current will flow from main line 92 through conductor I22, throughconductor I", through contact point Ill, through conducting strip I12,through contact point "3, through conductor I16, through conductor Ill,through contact point I32, through conducting strip I, through contactpoint I30, through conductor I42, thence through winding I, conductorI43, conductor H5, to the other side of the line 8|. This energizes thewinding I24 attracting the armature I23 and causing a reversal in thesame manner as heretofore described.

It will be seen that I have provided two independent means of initiatingthe reversal of the motor. Normally, I prefer to use the contactwhiskers since the surges of current throughthe windings produced bytemporary overloads tend to overheat the stator, which is not desirablein a deep well pump. The surges, however, are only momentary and Iprovide an eil'ective safety means for insuring a reversal of the motorin event the whisker contacts are not effective, through unforeseencircumstances.

It will be seen that I have accomplished the objects of my invention. Ihave provided a simple deep well pump of a reciprocating type and thusavoid the necessity of using long strings of sucker rods, thus savingtime, labor, and expense. My construction is an improvement over themechanical reversing means shown in my copending application, Serial No.328,419, in that no mechanical parts are required at the bottom of thewell. The relays for reversing the direction of rotation may be locatedon the surface and thus may be serviced from time to time without thenecessity of pulling the pump. The whisker relays may be so designedthat they will operate for long periods of time. The arrangement forproducing artificial overloads at the top and bottom of the strokeinsures, however, the reversal of direction of rotation of the motor,irrespective of whether the whisker relays become disarranged Or not.

It will be understood that certain features and sub-combinations are ofutility and may be employed without reference to other features andsub-combinations. This is contemplated by and is within the scope of myclaims. It is further obvious that various changes may be made indetails within the scope of my claims without departing from the spiritof my invention. It is. therefore, to be understood that my invention isnot to be limited to the specific details shown and described.

Having thus described my invention, I claim: 1. A reciprocating drivemechanism including in combination a housing, an alternating cur rentmotor in said housing, a screw adapted to be driven by said motor, a nutthreadedly mounted on said screw, coacting means on said housing andsaid nut for preventing rotation of said nut, reversing means for saidmotor, an actuating means for operating said reversing means, saidactuating means including an annular cylinder within said housingadjacent the upper limit of the travel of said nut, an annular cylinderwithin said housing adjacent the lower limit of the travel of said nut,an annular piston carried by said nut thereabove, an annular pistonsupported by said nut therebelow, said upper annular piston adapted toenter said upper annular cylinder and create an overload on said motorthereby, said lower annular piston adapted to enter said lower annularcylinder and create an overload on said motor thereby. and an overloadrelay responsive to the respective overloads created at the upper andlower limits of the travel of said nut for initiating the action of saidreversing means.

2. A reciprocating drive mechanism including in combination a housing,an alternating current motor in said housing, a screw adapted to bedriven by said motor, a nut threadedly mounted on said screw, coactingmeans on said housing and said nut for preventing rotation of said nut,said motor comprising a three-phase induction motor having a rotatingmagnetic field, reversing means for said motor including a reversingswitch ior reversing the connections of two or said field windings withrespect to each other whereby the direction oi rotation of said magneticfield is reversed, a latching relay for operating said reversing switch,a time delay relay for operating said latching relay, and meansresponsive to the movement of said nut for operating said time delayrelay.

3. A reciprocating drive mechanism including in combination a housing,an alternating current motor in said housing, a screw adapted to bedriven by said motor, a nut threadedly mounted on said screw, coactingmeans on said housing and said nut for preventing rotation of said nut,said motor comprising a three-phase induction motor having a rotatingmagnetic field, reversing means for said motor including a reversingswitch for reversing the connections of two of said field windings withrespect to each other whereby the direction of rotation of said mag-- 0means within said housing for creating an overload at the upper andlower limits of the reciproeating motion of said nut whereby to actuatesaid overload relay, and means responsive to the actuation 01 saidoverload relay for initiating the operation of said time delay relays tooperate said latching relay to energize said reversing switch to reversethe direction of rotation of said motor.

4, A reciprocating drive mechanism including in combination a housing,an alternating current motor in said housing, a screw adapted to bedriven by said motor, a nut threadedly mounted on said screw, coactingmeans on said housing and said nut for preventing rotation of said nut,said motor comprising a three-phase induction motor having a rotatingmagnetic field, rovers ing means for said motor including a reversingswitch for reversing the connections of two 0! said field windings withrespect to each other whereby the direction of rotation of said magneticfield is reversed, a latching relay for oper-- ating said reversingswitch, a time delay relay for operating said latching relay, anelectrical contact within said housing adjacent the upper limit ofmotion of said nut, a contact point within said housing adjacent thelower limit of travel of said nut, means carried by said nut forgrounding said contact points adjacent the upper and lower limits oftravel of said nut, and means responsive to the grounding of saidcontact points driven by said motor, a nut threadedly mounted on saidscrew, coacting means on said housing and said nut for preventingrotation of said nut, said motor comprising a three-phase inductionmotor having a rotating magnetic field, re-

versing means for said motor including a reversing switchv for reversingthe connections of two of said field windings with respect to each otherwhereby the direction of rotation of said magnetic field is reversed, alatchingrelay for operating said reversing switch, a time delay relayfor operating said latching relay, an electrical contact within saidhousing adjacent the upper limit of motion of said nut, a contact pointwithin said housing adjacent the lower limit or travel of said nut,means carried by said nut for grounding said contact points adjacent theupper and lower limits of travel of said nut, means responsive to thegrounding of said contact points for energizing said time delay. relayto operate said latching relay to operate said reversing switch toreverse the direction of rotation of said motor, and a hydraulic brakingmeans within said housing adjacent the upper and lower limits of travelof said nut. v

6. A reciprocating drive mechanism as in claim in which said hydraulicbraking means comprises an upper annular cylinder adapted to containoil, a lower annular cylinder adapted to con- ,tain oil, respectiveupper and lower annular pistons carried by said nut, said pistonsadapted to in said housing, a screw adapted to be driven by said motor,a nut threadedly mounted on said screw, coacting means on said housingand said nut for preventing rotation 01' said nut, reversing means forsaid motor including a reversing switch, electromagnetic means foroperating said reversing switch, a latching relay for operating saidelectromagnetic means, a relay for operating said latching relay, anoverload relay for operatin said last named relay, braking means withinsaid housing for braking, the travel of said nut adjacent its upper andlower limit of motion, said braking means adapted tocreate a motoroverload at the upper and lower limits of travel of said nut, whereby tooperate said overload relay to initiate the reversing of direction ofrotation of said motor.

8. A reciprocating drive mechanism comprising a housing, an inductionmotor within the housing, reversing means for the motor, an electricalcircuit for supplying current to the motor, a reciprocal means driven bysaid motor, means co-active with said reciprocal means at the ends ofits stroke to overload said circuit, and means responsive-to therespective overloads for actuating the said reversing means.

9. A reciprocating drive mechanism comprising a housing, an inductionmotor within the housactive with said reciprocal means at the ends ofits stroke to overload said circuit, and an over-' load relayioractuating the said reversing means.

' ARMAIS ARUTUNOFF.

